hi all,

updated on a prevoius post regarding my compression/leak problem in my frst engined 1800 zetec 16v turbo,

spoke to the head of a ford tuning,engine company, which is well known & long established,the advice he gave & very possible cause of my compression problem is....

"bore wash",excessive unburt fuel entering the chamber running down the side walls of the cylinders on to the rings, causing oil to be washed away leaving surfaces unlubracated then metal to metal contact,small bits of the piston above the top ring to ware away causing scoring on the walls of the bores,creating a poor seal leading to low compression & excessive pressure leakage,when a leak test is carried out.


what i would like to know is this a fesiable answer to my problem would a faulty fuel regulator,injectors cause such a problem?

the car is running the standard ecu,injectors,has a standard cossie fuel pump & frst fuel pressure regulator.


hope someone can shed some light on this suituation

 

come on you guys someone must be able to offer there advice

help me me get to the bottom of it

 

Not sure if borewash would cause scoring of the bores, maybe moreso glazing (very shiny, worn surface) of them, which will still give a poor seal to the piston rings.

Did any foreign object perhaps get through the intake system? Good air filter on the car? How bad are the bores, did you manage to get any compression readings?

 

has got an old pipercross induction filter off my old engine cleaned it & blew it out with an airline & re oiled it.

compression ratios taken just after car being on rollers,reading taken by the operator of the rolling road.

as follows

1 38% 125

2 78% 60

3 58% 115

4 70% 100

when pistons where removed quite a high amount of black carbon on top of pistons,but clean on the back section of at least two pistons would indicate to me that fuel has washed that section clean.

engine has been full rebuilt head has been pressure tested,all new gaskets,seals,bearings,pumps,rings,oil spray jets under pistons

engine has done 1800 miles,1500 miles on cheap run in thick oil,then changed to castrol rs 10/60,boost set low at 7psi,with new recon t3

hope this helps, any other info just ask

 

bore are scored enough that your finger nail sits in some of the bad ones

not really sure which way to go untill i have got to the bottom of this

 

Not really familiar with the engine conversion itself - is the engine originally turbo'd? My reason for asking this is - is the fuelling set by the ECU, via injectors, correct for the boost pressure etc... you're running?

 

no engine is standard with proper laser cut de-comp plate that is a prefect match to geniune headgasket
ecu is standard o-fac which is suitable for this application,

car was set up to a safe fuel level,up untill this problem occoured.

i drove the car back from the garage approx done 200 miles since car has never run so good since being on the rollers

 

Did you notice any other symptoms of overfuelling? Smoking from exhaust, excessive consumption etc..?

The question about ECU and engine was to make sure the car wasn't underfuelling, causing detonation and overheating. Then again you'd see heat damage to pistons etc.. (had that on as S1 I owned - melted piston and bore scored).

I had a 1430cc mini once that suffered with overfuelling via a twin choke weber - that just gave accelerated bore wear and very glazed finish, but no scoring at all.

I think it is more likely to be due to foreign matter through the intake or the rings themselves damaging the bores for some reason from startup. Perhaps attach a couple of pics of the bores/pistons?

 

will try & get some pics up for you,

have drove car to ford fair from Devon using under a tank of fuel.

starter has been giving me a bit of greif won't start when its hot,apparantly a common fault on s2 turbos as starter is close to down pipe,

car did start to smoke on rollers after adjustments where made to fueling & boost on initinal set-up b4 we had to stop set-up after we came across this problem we have now with the compression.

when engine was being run in i just made slight adjustments to fueling to make it idle ,tick over nice

 

I hope that the AFRs have been checked or the management remapped after the engine swap?

 

overfueling definately wears bores down faster.
i have a standard 1800 block going if yu need one
mike